The present invention relates to water-filtration systems, and more particularly, the present invention relates to modular-filter based UV-irradiated water purification systems for home and garden.
It is well known in the prior art to utilize particulate filters and reverse-osmosis filters to clear source water of particles of certain size and to eliminate certain chemicals and ions from the source water. It is also known in the art to utilize UV-irradiation of source water to neutralize possible pathogens and micro-organisms in the source water. In some instances, a storage tank may be used to house filtered and cleaned water for dispensation through a tap. All of such devices generally rely upon a single pass through the filtration system, and none have yet optimized a system for multiple UV-irradiation runs of source water to tap. In a reverse osmosis system using a UV filter the design is typically to put the UV filter at the end of the system immediately prior to the point of use to ensure the water dispensed is sterile. Alternatively, a system designer may place the UV filter before the storage vessel where the flow rate is slower to enhance the sterilizing dose and prevent the storage vessel and thus the system from becoming a potential breeding ground for microorganisms.
The present invention, FULL CONTACT UV, is a modular-filter based reverse osmosis system with a ultra-violet (UV) sterilization system whereby the purified water is channeled through the same UV filter cartridge twice to eliminate 99.99% of the flow of microorganisms into the storage vessel—a potential breeding point—and to again 99.99% eliminate the flow of microorganisms into the point of use without having to use two separate UV filters. It has been found that certain storage systems, particularly for agricultural based purified water, can be the breeding ground for unwanted pathogens or microorganisms, and may offer an opportunity for post-treated water to become contaminated.
Additionally, while reverse osmosis membranes filter at a level finer than any bacteria or virus, they will develop micro-tears during their lifecycles which permits the breakthrough of microorganisms into the product water even while the membrane is operating within accepted tolerances. In addition, storage in a tank may allow for entry and proliferation of certain unwanted materials and/or organisms that may adversely affect the quality of the water. To protect the reverse osmosis product water stream from contamination by any microorganism breakthrough, a UV-sterilizing filter can now be employed after the reverse osmosis membrane. In the past, UV filters are not used before the RO membrane because they can quickly be rendered ineffective by staining elements such as iron or magnesium, and microorganisms can be shielded from the sterilizing UV light by suspended solids or clumps of particulates. Typical reverse osmosis systems using one UV filter will only sterilize the water at one point either before the storage tank or at the end of the system prior to the point of use. In reverse osmosis systems a UV filter can be placed before the storage vessel to ensure general system hygiene and prevent the storage tank from becoming a breeding ground for microorganisms.
However, prior art designs do not prevent the growth and spread of pre-existing microorganisms between the UV filter and the point of use at dispensation. Locating the UV filter at the end of the system just prior to the point of use ensures the product water is 99.99% sterile (providing the UV filter flow rate is properly matched to the system product flow rate), but it leaves the storage vessel and other upstream system components exposed, creating the possibility of a dangerous level of microorganism breakthrough if the UV filter failed even briefly. Sterilizing RO water is not new, and neither is using a modular-filter based RO system. The present invention teaches a FULL CONTACT UV design by which purified water is forced through a single UV filter cartridge two times, and using it on a modular-filter based platform. Our search revealed no existing products or patents related to the use of our FULL CONTACT UV double UV sterilization system used in conjunction with a modular-filter based RO system.
Similar inventions that provided vast steps forward in water purification technology include the FULL CONTACT ARTESIAN forced double remineralization system as shown in U.S. Pat. No. 7,507,334 to Sigona, incorporated herein by reference. The FULL CONTACT ARTESIAN UV system is the next evolution in the purification of water. This invention is non-obvious to one having ordinary skill in the art, and created after 5 years of testing in the area of UV, RO and sterilization systems and remineralization systems!
The major significant difference between a canister filter based RO system, and a modular filter based RO system is that the canister filter based RO system uses canister filter housings with replaceable filter elements. The filters are changed periodically, but the canister filter housings remain. The owner's manuals of these types of systems urge the user to replace the canister filter housings regularly, usually about once every 5 years, however the vast majority of users do not do this, and the housings will weaken and burst with age potentially causing significant water damage to the user's residence or workplace. Our system—a modular filter based RO system—uses modular filters, where the filter and its housing are molded together and both together are replaced annually or as needed. This prevents the possibility of the filter housing aging and bursting as with the canister filter based system. It is also contemplated that the filters may not be modular and may also include other filter types, such as a canister filter and other filters used in the art of water treatment.
Reverse osmosis system manufacturers have long used UV sterilization as a supplement to their systems to ensure product water potability and/or protect system components. However, those systems could only achieve one of those goals or the other unless they used two UV filters in their system. For example: we offer our TAP MASTER UV Series modular-filter based reverse osmosis system with a UV Filter located prior to the storage tank. We chose this location because the flow rate at this point is very slow, far below the flow rate maximum allowable to ensure 99.99% sterilization, and thus with the increased contact time the sterilizing dosage of UV light can be increased 10 times or more. The drawback is that any pre-existing microorganisms downstream of the UV filter will not be treated. This is the choice every RO with UV system designer had to make—before the storage tank to protect the system and take advantage of the higher UV dosing that comes with the slower flow rate, or place the UV filter at the end of the system to ensure all the water dispensed is treated and hope that the flow rate doesn't exceed specs or the UV light doesn't fail or flicker—until this invention. The water treatment system we present to you here—The FULL CONTACT UV forces the water through the same UV filter twice—once on the way to the storage vessel and once again just prior to the point of use ensuring both system hygiene, and sterilization just prior to the point of use.
Furthermore, the FULL CONTACT UV system is ideal for agricultural purposes. The purpose of irrigation is to minimize the deleterious effects of water stress on growth and yields. Irrigation is necessary to achieve maximum growth and yields over a wide range of growing conditions. The amount of irrigation varies with growing conditions. Irrigation is improved with purified water treatments. Water free of water-borne contaminants in a purified form is beneficial for plants to take up water. Random free ions interfere with water uptake and nutrient load.
Several micro-irrigation systems have been developed that deliver relatively small volumes of water at fairly frequent intervals, thus minimizing the large diurnal variations in soil and plant water status that commonly occur with furrow irrigation. Drip, or trickle, irrigation emitters typically deliver 1-2 gallons per hour and micro-sprinkler systems deliver 5-20 gallons per hour. With escalating costs and lack of availability of high-quality water, micro-irrigation is becoming widely used throughout the world and may continue to be the method of choice in many growing regions.
Micro-irrigation systems provide an efficient method of providing water on a consistent basis; however they require intensive management. Irrigation lines are subject to clogging by particulate matter, insects, spiders, or minerals such as calcium or magnesium which precipitate from the irrigation water. Various iron and sulfur reducing bacteria and algae also cause plugging of emitters. Therefore, water quality and adequate filtration and chlorination (to control algae and bacteria) are necessary to ensure proper operation of the system. Moreover, salts (NA, Cl) may accumulate in and around emitters especially in arid regions, in some cases causing root damage if they are not periodically leached from around the roots.
Traditionally, fertilizer has been banded or broadcast in granular form; however, more recently liquid fertilizer is being applied through irrigation lines (fertigation) in many areas of the world. Some studies suggest that frequent application of low levels of liquid fertilizer improves plant growth over less frequent applications. The theory being that the concentration of nutrients is maintained at a constant level in the soil solution thus allowing continual uptake. Other studies, however, show that frequent fertilization in granular form compared with liquid fertilizer has no effect of growth, possibly because plants take up and store N as amino acids to be used for subsequent growth.
There has been considerable interest in using controlled-release/slow-release fertilizers which reduce the number of fertilizer applications needed per year, and losses due to leaching. Several products are available that have potential, especially in isolated replant situations. The major drawback to acceptance of controlled-release materials it he high cost per unit.
Therefore, there is a need to provide particulate free, ion free and/or sterilized water for irrigation purposes.
Therefore, it is an object of the present invention to produce purified and sterile water from a reverse osmosis system. It is another object of the present invention to produce purified and sterile water from a reverse osmosis system with sterilization taking place before the storage tank and immediately prior to the point of use without the inherent liability of the canister filter based reverse osmosis system. It is still another object of the present invention to produce purified water using UV-exposure. It is a further object of the present invention to conduct sterilization without using multiple UV filters. Furthermore, it is yet another object of the present invention to produce purified and sterile water from a reverse osmosis system with sterilization taking place before the storage tank and immediately prior to the point of use with the inherent benefits of modular filter based reverse osmosis system, and without using multiple UV filters. These and other objects of the present invention will become apparent to those skilled in the art as the description proceeds.